This software allows you to download covers for all your movies. Instead of downloading every cover manually, you can just run this software and select the folder containing your movies. The software will do the rest and add the correct cover to each of your movies.
Important: Make sure that your movie files are named properly!
As far as I know, there is no other software doing the same stuff. Just try it out and you will see, how easy and helpful this tool can be, especially if you have lot of movies on your harddisk.